Vacuum planters are often used to plant any of a variety of seeds, including seeds with odd shapes, such as corn seeds, pumpkin seeds, soybean seeds, among others. These planters have vertical plates with holes that are smaller than the seeds being planted. The planter draws a vacuum on the side of the plate opposite the container in which the seeds are stored. When the plate rotates through the storage container, atmospheric pressure holds seeds against the holes and allows the rotating plate to pick up seeds. As the plate rotates around past the seed tube, the vacuum is broken, allowing the seeds to drop down a seed tube.
There are several important features associated with the use of, in particular, vacuum plants, in the planting of seeds. First, vacuum planters have a tendency to release a certain amount of seed dust during planting. This dust may include active ingredients, such as insecticides, nematicides, fungicides, and other pesticides that have been combined with the seed. The loss of such active ingredients during planting is undesirable. Second, is seed singulation. Seed singulation refers to the ability of a planter to take one seed at a time off the vertical plate and drop it down the seed tube. Maximizing seed singulation is also important. Skipped seed drops can create a loss within the planting row, while doubles increase population and cause the plants to struggle for nutrients and sunlight. Historically, small differences in seed type can affect singulation percentage. Third, it is important that the seed have a good ability to flow from the seed hopper to the seed meter reservoir. Good seed flow characteristics allow for longer operating time per hopper fill and reduces mechanical wear on planter parts, thus extending the operating life of the planter.
To address these issues, a polymer binder and/or lubricant is often included with the active ingredients in the treatment of seeds to bind the active ingredient to the seed. Seeds treated in such a manner can have reduced dust and increased percent singulation and flow during planting, particularly vacuum planting, relative to when a polymer binder is not used. Historically, this polymer binder has been a polyolefin, such as a carboxylated styrene/butadiene dispersion.
A drawback to the use such polyolefin binders, however, is that they are not biodegradable and, as a result, can accumulate in the soil. As a result, it would be desirable to provide an alternative to such seed treatments that perform in a comparable manner and which are at least partially disintegrable by moisture in the soil.